The mayor's action came amid an outcry that the event would take away from efforts to help thousands of New Yorkers who are without power or homeless because of superstorm Sandy.

"While holding the race would not require diverting resources from the recovery effort, it is clear that it has become the source of controversy and division," the mayor said in a statement. "The marathon has always brought our city together and inspired us with stories of courage and determination. We would not want a cloud to hang over the race or its participants, and so we have decided to cancel it."

He added, "We cannot allow a controversy over an athletic event – even one as meaningful as this – to distract attention away from all the critically important work that is being done to recover from the storm and get our city back on track."

Bloomberg had been consulting this evening with the New York Road Runners, the organization behind the annual race this evening.

It's the first time the race has ever been canceled.

Marry Wittenberg, CEO of the Road Runners Club, said their original intention had been to "honor those who've been hurt on this tragic storm and move this city forward."

But the controversy overwhelmed the race officials in recent days. "It was time to move and let this city focus" on recovery efforts.

"It was time to make this decision. This became a psychological issue for the city," she said.

Wittenberg said they considered "alternate distances... to shorten the race" in order to salvage it, but a decision had to be made because "people are flying in tomorrow, coming in from across the nation and the world."

Earlier this week Bloomberg insisted the race would go on. "[New York] has to show that we are here and we are going to recover, [and] give people something to cheer about in what's been a very dismal week for a lot of people," the mayor said.

The marathon traditionally starts at Fort Wadsworth on Staten Island, one of the hardest hit communities in New York City. More than 80,000 residents were still without power and many remained homeless. At least 19 people also died on Staten Island because of Sandy.

Staten Island Borough President James Molinaro called plans to race "crazy" and City Council President Christine Quinn, a Bloomberg loyalist, said, "The decision to move forward with the marathon is not a decision I would have made."

Before Bloomberg's announcement tweets blasting the decision to proceed with the marathon had increased from about 10,000 tweets to more than 50,000.